1. , and , Conservation laws of mixed type describing three-phase flow in porous media, Exxon Production Research, preprint, 1985.
2. A continuum model for two-directional traffic flow
3. , , and , The classification of solutions of quadratic Riemann problems (I), Mathematical Research Center, Wisconsin, preprint, 1985.
4. and , The classification of solutions of quadratic Riemann problems (II), Mathematical Research Center, Wisconsin, preprint, 1985.